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BATTLE // -217 BCE

Battle of the Trebia

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Overview

The Battle of the Trebia was the first major battle of the Second Punic War, fought between the Carthaginian forces of Hannibal and a Roman army under Sempronius Longus on 22 or 23 December 218 BC. Each army had a strength of about 40,000 men; the Carthaginians were stronger in cavalry, the Romans in infantry. The battle took place on the flood plain of the west bank of the lower Trebia River, not far from the settlement of Placentia, and resulted in a heavy defeat for the Romans.

Overview adapted from Wikipedia, licensed under CC BY-SA 4.0.

Significance

The Battle of the Trebia was the first major engagement of the Second Punic War, fought on the flood plain of the west bank of the lower Trebia River near Placentia. With each side fielding approximately 40,000 men, the battle ended in a heavy Roman defeat, with Roman casualties reaching 20,000. The outcome demonstrated early in the conflict that Hannibal's army — superior in cavalry to the Roman force under Sempronius Longus — could inflict decisive losses on a Roman army in open battle on Italian soil. As the opening major battle of the war, the Trebia established Hannibal's capacity to operate aggressively in northern Italy and set the conditions for subsequent Carthaginian advances deeper into the peninsula.

Forces & casualties

Troop strength

  • Carthage40,000
    medium
  • Rome40,000
    medium

Both sides were near-evenly matched in numbers

Casualties

  • Rome20,000
    medium50% loss rate

Commanders (2)

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6 sibling battles · 0 factions

Last verified July 2026
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